EndeF celebrates its 4th anniversary and, as every time the anniversary and the long and sunny days come, EndeF thinks about how much solar energy we waste. These ENERGY thoughts have led us to calculate how many photovoltaic panels would the city of Zaragoza (700,000 inhabitants) need to produce all the electricity that is consumed in a year.

To find out, we assume that the solar energy that a panel can achieve when installed in Zaragoza with 32º is 1971 kWh/m2yearly. Taking into account a solar efficiency of 15 % and 30 % of losses, the final useful value is 207 kWh/ m2yearly.In the doctoral thesis of Eduardo Garcia Paricio presented in 2015 at the University of Zaragoza, he states that the global area of roofs for both residential and buildings in this city is 24,853,491 m2. In addition, the website of Zaragoza’s local government, within the Strategy for Sustainable Energy Management, publishes energy consumption data. In the 2014 publication, it indicates that total electricity consumption is 296,250 tep yearly in Saragossa, ie 3,445,388 MWh.

With a simple division, it can be estimated that with 66% of the covers currently available in Zaragoza all The electricity consumed in the city could be obtained. We must not forget that shades or inclination will make some of these covers unsuitable; on the other hand, part of the electricity consumed in Saragossa is already produced by renewable energy. In addition to this, we would not need to occupy lands will solar panels, we are talking about the floor area already built up.

It seems common sense to try to make the most of this solar energy, so as not to hinder their development and encourage its use with batteries in order to get a clean, stable, secure and democratic energy system.